If you control more than one Oracle of Mul Daya, the effects of their first abilities are cumulative. If you control two, for example, you can play three lands on your turn.

10/1/2009

Oracle of Mul Daya doesn’t change the times when you can play a land card from the top of your library. You can play a land only during your main phase when you have priority and the stack is empty. Doing so counts as one of your land plays for the turn.

10/1/2009

If you play your first land of the turn from the top of your library, and the new top card is another land card, you can play that one too.

4/15/2013

The top card of your library isn’t in your hand, so you can’t suspend it, cycle it, discard it, or activate any of its activated abilities.

4/15/2013

If the top card of your library changes while you’re casting a spell, playing a land, or activating an ability, the new top card won’t be revealed until you finish doing so.

4/15/2013

When playing with the top card of your library revealed, if an effect tells you to draw several cards, reveal each one before you draw it.